ogrmysqldatasource.cpp

来自「支持各种栅格图像和矢量图像读取的库」· C++ 代码 · 共 1,104 行 · 第 1/3 页

    char            szCommand[1024];
    MYSQL_RES       *hResult;
    OGRErr	    eErr = OGRERR_NONE;
 
    sprintf( szCommand, "DESCRIBE geometry_columns" );
    if( mysql_query(GetConn(), szCommand ) )
    {
        sprintf(szCommand,
                "CREATE TABLE geometry_columns "
                "( F_TABLE_CATALOG VARCHAR(256), "
                "F_TABLE_SCHEMA VARCHAR(256), "
                "F_TABLE_NAME VARCHAR(256) NOT NULL," 
                "F_GEOMETRY_COLUMN VARCHAR(256) NOT NULL, "
                "COORD_DIMENSION INT, "
                "SRID INT,"
                "TYPE VARCHAR(256) NOT NULL)");
        if( mysql_query(GetConn(), szCommand ) )
        {
            ReportError( szCommand );
            eErr = OGRERR_FAILURE;
        }
        else
            CPLDebug("MYSQL","Creating geometry_columns metadata table");
 
    }
 
    // make sure to attempt to free results of successful queries
    hResult = mysql_store_result( GetConn() );
    if( hResult != NULL )
    {
        mysql_free_result( hResult );
        hResult = NULL;   
    }
 
    sprintf( szCommand, "DESCRIBE spatial_ref_sys" );
    if( mysql_query(GetConn(), szCommand ) )
    {
        sprintf(szCommand,
                "CREATE TABLE spatial_ref_sys "
                "(SRID INT NOT NULL, "
                "AUTH_NAME VARCHAR(256), "
                "AUTH_SRID INT, "
                "SRTEXT VARCHAR(2048))");
        if( mysql_query(GetConn(), szCommand ) )
        {
            ReportError( szCommand );
            eErr = OGRERR_FAILURE;
        }
        else
            CPLDebug("MYSQL","Creating spatial_ref_sys metadata table");
 
    }    
 
    // make sure to attempt to free results of successful queries
    hResult = mysql_store_result( GetConn() );
    if( hResult != NULL )
    {
        mysql_free_result( hResult );
        hResult = NULL;
    }
 
    return eErr;
}

/************************************************************************/
/*                              FetchSRS()                              */
/*                                                                      */
/*      Return a SRS corresponding to a particular id.  Note that       */
/*      reference counting should be honoured on the returned           */
/*      OGRSpatialReference, as handles may be cached.                  */
/************************************************************************/

OGRSpatialReference *OGRMySQLDataSource::FetchSRS( int nId )
{
    char         szCommand[1024];
    char           **papszRow;  
    MYSQL_RES       *hResult;
            
    if( nId < 0 )
        return NULL;

/* -------------------------------------------------------------------- */
/*      First, we look through our SRID cache, is it there?             */
/* -------------------------------------------------------------------- */
    int  i;

    for( i = 0; i < nKnownSRID; i++ )
    {
        if( panSRID[i] == nId )
            return papoSRS[i];
    }

    OGRSpatialReference *poSRS = NULL;
 
    // make sure to attempt to free any old results
    hResult = mysql_store_result( GetConn() );
    if( hResult != NULL )
        mysql_free_result( hResult );
    hResult = NULL;   
                        
    sprintf( szCommand,
         "SELECT srtext FROM spatial_ref_sys WHERE srid = %d",
         nId );
    
    if( !mysql_query( GetConn(), szCommand ) )
        hResult = mysql_store_result( GetConn() );
        
    char  *pszWKT = NULL;
    papszRow = NULL;
    

    if( hResult != NULL )
        papszRow = mysql_fetch_row( hResult );

    if( papszRow != NULL && papszRow[0] != NULL )
    {
        pszWKT =papszRow[0];
    }

    // make sure to attempt to free results of successful queries
    hResult = mysql_store_result( GetConn() );
    if( hResult != NULL )
        mysql_free_result( hResult );
	hResult = NULL;
		
     poSRS = new OGRSpatialReference();
     if( pszWKT == NULL || poSRS->importFromWkt( &pszWKT ) != OGRERR_NONE )
     {
         delete poSRS;
         poSRS = NULL;
     }

/* -------------------------------------------------------------------- */
/*      Add to the cache.                                               */
/* -------------------------------------------------------------------- */
    panSRID = (int *) CPLRealloc(panSRID,sizeof(int) * (nKnownSRID+1) );
    papoSRS = (OGRSpatialReference **) 
        CPLRealloc(papoSRS, sizeof(void*) * (nKnownSRID + 1) );
    panSRID[nKnownSRID] = nId;
    papoSRS[nKnownSRID] = poSRS;

    return poSRS;
}



/************************************************************************/
/*                             FetchSRSId()                             */
/*                                                                      */
/*      Fetch the id corresponding to an SRS, and if not found, add     */
/*      it to the table.                                                */
/************************************************************************/

int OGRMySQLDataSource::FetchSRSId( OGRSpatialReference * poSRS )

{
    char           **papszRow;  
    MYSQL_RES       *hResult=NULL;
    
    char                szCommand[10000];
    char                *pszWKT = NULL;
    int                 nSRSId;

    if( poSRS == NULL )
        return -1;

/* -------------------------------------------------------------------- */
/*      Translate SRS to WKT.                                           */
/* -------------------------------------------------------------------- */
    if( poSRS->exportToWkt( &pszWKT ) != OGRERR_NONE )
        return -1;
    
    CPLAssert( strlen(pszWKT) < sizeof(szCommand) - 500 );

/* -------------------------------------------------------------------- */
/*      Try to find in the existing table.                              */
/* -------------------------------------------------------------------- */
    sprintf( szCommand, 
             "SELECT srid FROM spatial_ref_sys WHERE srtext = '%s'",
             pszWKT );

    if( !mysql_query( GetConn(), szCommand ) )
        hResult = mysql_store_result( GetConn() );

    if (!mysql_num_rows(hResult))
    {
        CPLDebug("MYSQL", "No rows exist currently exist in spatial_ref_sys");
        mysql_free_result( hResult );
        hResult = NULL;
    }
    papszRow = NULL;
    if( hResult != NULL )
        papszRow = mysql_fetch_row( hResult );
        
    if( papszRow != NULL && papszRow[0] != NULL )
    {
        nSRSId = atoi(papszRow[0]);
        if( hResult != NULL )
            mysql_free_result( hResult );
        hResult = NULL;
        return nSRSId;
    }

    // make sure to attempt to free results of successful queries
    hResult = mysql_store_result( GetConn() );
    if( hResult != NULL )
        mysql_free_result( hResult );
    hResult = NULL;

/* -------------------------------------------------------------------- */
/*      Get the current maximum srid in the srs table.                  */
/* -------------------------------------------------------------------- */
    sprintf( szCommand, 
             "SELECT MAX(srid) FROM spatial_ref_sys");    
    if( !mysql_query( GetConn(), szCommand ) )
    {
        hResult = mysql_store_result( GetConn() );
        papszRow = mysql_fetch_row( hResult );
    }
        
    if( papszRow != NULL && papszRow[0] != NULL )
    {
        nSRSId = atoi(papszRow[0]) + 1;
        if( hResult != NULL )
            mysql_free_result( hResult );
        hResult = NULL;
    }
    else
        nSRSId = 1;
    
/* -------------------------------------------------------------------- */
/*      Try adding the SRS to the SRS table.                            */
/* -------------------------------------------------------------------- */
    sprintf( szCommand, 
             "INSERT INTO spatial_ref_sys (srid,srtext) VALUES (%d,'%s')",
             nSRSId, pszWKT );

    if( !mysql_query( GetConn(), szCommand ) )
        hResult = mysql_store_result( GetConn() );

    // make sure to attempt to free results of successful queries
    hResult = mysql_store_result( GetConn() );
    if( hResult != NULL )
        mysql_free_result( hResult );
    hResult = NULL;
           
    return nSRSId;
}

/************************************************************************/
/*                             ExecuteSQL()                             */
/************************************************************************/

OGRLayer * OGRMySQLDataSource::ExecuteSQL( const char *pszSQLCommand,
                                        OGRGeometry *poSpatialFilter,
                                        const char *pszDialect )

{
    if( poSpatialFilter != NULL )
    {
        CPLDebug( "OGR_MYSQL", 
          "Spatial filter ignored for now in OGRMySQLDataSource::ExecuteSQL()" );
    }

/* -------------------------------------------------------------------- */
/*      Use generic implementation for OGRSQL dialect.                  */
/* -------------------------------------------------------------------- */
    if( pszDialect != NULL && EQUAL(pszDialect,"OGRSQL") )
        return OGRDataSource::ExecuteSQL( pszSQLCommand, 
                                          poSpatialFilter, 
                                          pszDialect );

/* -------------------------------------------------------------------- */
/*      Special case DELLAYER: command.                                 */
/* -------------------------------------------------------------------- */
#ifdef notdef
    if( EQUALN(pszSQLCommand,"DELLAYER:",9) )
    {
        const char *pszLayerName = pszSQLCommand + 9;

        while( *pszLayerName == ' ' )
            pszLayerName++;

        DeleteLayer( pszLayerName );
        return NULL;
    }
#endif

/* -------------------------------------------------------------------- */
/*      Make sure there isn't an active transaction already.            */
/* -------------------------------------------------------------------- */
    InterruptLongResult();

/* -------------------------------------------------------------------- */
/*      Execute the statement.                                          */
/* -------------------------------------------------------------------- */
    MYSQL_RES *hResultSet;

    if( mysql_query( hConn, pszSQLCommand ) )
    {
        ReportError( pszSQLCommand );
        return NULL;
    }

    hResultSet = mysql_use_result( hConn );
    if( hResultSet == NULL )
    {
        if( mysql_field_count( hConn ) == 0 )
        {
            CPLDebug( "MYSQL", "Command '%s' succeeded, %d rows affected.", 
                      pszSQLCommand, 
                      (int) mysql_affected_rows(hConn) );
            return NULL;
        }
        else
        {
            ReportError( pszSQLCommand );
            return NULL;
        }
    }

/* -------------------------------------------------------------------- */
/*      Do we have a tuple result? If so, instantiate a results         */
/*      layer for it.                                                   */
/* -------------------------------------------------------------------- */

    OGRMySQLResultLayer *poLayer = NULL;

    poLayer = new OGRMySQLResultLayer( this, pszSQLCommand, hResultSet );
        
    return poLayer;
}

/************************************************************************/
/*                          ReleaseResultSet()                          */
/************************************************************************/

void OGRMySQLDataSource::ReleaseResultSet( OGRLayer * poLayer )

{
    delete poLayer;
}

/************************************************************************/
/*                            LaunderName()                             */
/************************************************************************/

char *OGRMySQLDataSource::LaunderName( const char *pszSrcName )

{
    char    *pszSafeName = CPLStrdup( pszSrcName );
    int     i;

    for( i = 0; pszSafeName[i] != '\0'; i++ )
    {
        pszSafeName[i] = (char) tolower( pszSafeName[i] );
        if( pszSafeName[i] == '-' || pszSafeName[i] == '#' )
            pszSafeName[i] = '_';
    }

    return pszSafeName;
}

/************************************************************************/
/*                         RequestLongResult()                          */
/*                                                                      */
/*      Layers need to use mysql_use_result() instead of                */
/*      mysql_store_result() so that we won't have to load entire       */